Laser Thermal Treatment‐Induced Mg_xZn_1−xO Gradient Film and Photodetector with Solar‐Blind UV Response

Abstract

Mg x Zn1−x O is a ternary oxide semiconductor, which has an important application prospect in solar‐blind UV detection fields. Herein, Mg x Zn1−x O gradient film is realized utilizing the sol–gel method and laser thermal treatment process. X‐ray diffraction (XRD) pattern and absorption curve show that the gradient film has a single (002) crystal orientation and a single absorption edge. Field‐emission scanning electron microscope and energy‐dispersive spectroscopy characterization and finite‐element analysis simulation prove that the laser thermal treatment temperature on the gradient film decreases from 1100 to 600 °C, corresponding to the Mg2+ component gradually increasing from 35% to 54% and the bandgap broadening from 3.75 to 5.08 eV. Metal–semiconductor–metal‐structured photodetectors (PDs) are fabricated based on the gradient film. The high responsivity is attributed to the capture and the prolonged lifetime of photogenerated holes. Herein, an idea for the preparation of gradient film and the development of UVC and UVA multiband PDs is provided.

Enhanced Performance of Self-Powered Ga2O3/ZnO:V Heterojunction Solar-Blind Ultraviolet Photodetectors by Coupling Ferroelectricity and Piezoelectricity

“…Solar-blind ultraviolet (SBUV) photodetectors (PDs) are widely used in various fields of the civilian and military, such as environmental monitoring, biometric identification, missile alerts, and secure communication. − Wide band gap semiconductor materials including Al x Ga 1– x N ( E g = 3.4–6.2 eV), Mg x Zn 1– x O ( E g = 3.7–7.8 eV), and Ga 2 O 3 ( E g = 4.4–5.1 eV) have been the subject of thorough investigations as promising candidates for the fabrication of SBUV PDs. In Al x Ga 1– x N or Mg x Zn 1– x O, − increasing the Al or Mg mole fractions in the alloy films results in the defect density increasing significantly or in phase separation, leading to severe deterioration in PD performance. Ga 2 O 3 appears to be an ideal candidate for SBUV PDs due to its suitable band gap, large absorption coefficient, and excellent thermal and chemical stability. − In general, Ga 2 O 3 SBUV PDs can be divided into a photoconductive type and self-powered type (photovoltaic type).…”

Ga2O3 Schottky Avalanche Solar‐Blind Photodiode with High Responsivity and Photo‐to‐Dark Current Ratio

“…[10,11] Recent development of wide bandgap semiconductors such as MgZnO, AlGaN, and Ga 2 O 3 allow to realize solar-blind photodetection without optical DOI: 10.1002/aelm.202300297 filters. [12][13][14][15][16][17][18][19][20][21] Among them, Ga 2 O 3 is considered as an ideal candidate due to its suitable bandgap (≈4.8 eV), high thermal stability, and large absorption coefficient. In real applications, the detected solarblind signals are generally weak due to severe environmental absorption, and thus most solar-blind photodetectors require high responsivity (R) and high photo-todark current ratio (PDCR) to enhance the detection quality and sensitivity.…”